Notes: Network average numbers from the week prior are based on preliminary data. Comparison’s from the week prior (or episode-to-episode, etc.) on specific shows are based on final national data. Ratings for the current day are based on preliminary data. (Expect all three scenarios to be the case at all times, unless otherwise noted). The final numbers for first-run episodes that aired this evening will be reported the following week. So for example, the final numbers for tonight’s episode of “CSI: Crime Scene Investigation” will be reported in next weeks report for Thursday, April 22 2010. Also keep in mind that because these are preliminary numbers, when the finals are released there may be noticeable changes.

And lastly, there may be some errors in the data due to rounding/human error. I’ll do my best to limit those mistakes and correct them in time for the next week’s report.

Source: The Nielsen Company | Ratings information on this page consists of Preliminary and/or Final National numbers which include both Live viewing and DVR playback for the Same Day (defined as Live + Same Day or 3am-3am viewing). | Daily ratings figures can be found at PI Feedback, Zap2It and TV by the Numbers.